Christian Flannery was out walking the dogs with his father beside the family home at Killock, Clerihan, Clonmel in Co Tipperary when the incident happened on May 20, last year.

Dublin Coroner's Court heard that he was rushed to hospital and, initially, it looked like he would make a recovery following emergency surgery. However he suffered an aneurysm leading to his death at Temple Street Children's Hospital a month later on June 19.

His father, Paddy Flannery, told the inquest that he knew something was seriously wrong when he heard his son crying out after he was struck.

"We had finished galloping the dogs. Christian went over to a gate that was partially open. The dogs were on one side of the gate and Christian was on the other. The dogs were running and jumping and one of the dogs hit the gate causing it to swing forward and hit Christian on the side of the forehead," he said.

"He fell to the ground and I could hear him cry. I knew instantly it wasn't a normal cry. I immediately called '999' the minute I saw him."

Christian was taken by ambulance to South Tipperary General Hospital where CT scans showed multiple fractures of the skull. He was transferred to Temple Street Hospital and that evening underwent emergency surgery.

Consultant neurosurgeon at Temple Street Mr Darach Crimmins said the fractures were extensive and there was tearing in the dura (lining) of the brain and bleeding on the brain.

He removed all of the blood in so far as he could, he said, repaired the laceration of the dura and repaired the skull using multiple re-absorbable plates.

Christian required a further operation to relieve pressure on the brain on May 28. On June 3, Christian's condition deteriorated suddenly.

Mr Crimmins said a CT scan showed a "horrendous haemorrhage" on the left side of the brain.

"We discussed the case with Christian's family and we felt that this degree of new injury was incompatible with any meaningful survival," he said.

He told the court that prior to the haemorrhage from the aneurysm, Christian was in recovery.

No further active treatment was carried out and Christian died on June 19.

At post-mortem, pathologist Dr Deirdre Devaney found that Christian had suffered a "rare, uncommon" complication in his head injury where tiny fragments of fractured bone damaged the middle meningeal artery in the brain leading to the aneurysm. These fractured pieces likely embedded at the time of the original accident, she said.

Coroner Dr Brian Farrell returned a verdict of accidental death. Following the inquest, Mr Flannery thanked the staff at Temple Street Hospital. "They did everything above the call of duty but it just wasn't to be," he said.